A variety of different fire detection systems are known which utilize camera vision for purposes of monitoring the region. Signals from the camera or cameras in known systems, can be processed to evaluate flames within the field of view of the cameras.
Many of the known systems have a significant problem detecting smoke at night. They require that the lights in the region being monitored remain ON or that accessory lighting be provided in the area so the camera can detect changes. The primary problem with this is that a fire detecting system must have an ability to operate normally in the absence of power in the building. Therefore, at least some of the lighting would need to have battery back-up. The high power lighting of an area being monitored can make the battery back-up expensive. These systems often do not work well at night for detecting smoke in the absence of supplemental illumination. Flames can be detected at any time of day/night. Smoldering fires, however, are not readily detected in the absence of supplemental lighting which requires battery backup. Hence, these systems may not pass agency approvals as smoke detection systems.
Alternately, projected beam of smoke detectors are known. In these detectors, a beam of light is projected through an area being monitored. Exit beam characteristics are evaluated for the presence of smoke. While projected beam smoke detectors are useful and effective for their intended purpose, they represent an expense which is directed to implementing a single purpose function, namely smoke detection.
There continues to be a need for systems that are able to provide a fire detection function in combination with cameras which can also be used for security monitoring of an area or region. Such multi-purpose systems should be more cost effective than two separate systems. Additionally, such integrated systems may provide opportunities to cost effectively detect smoke under decreased lighting conditions or in dark regions.